Gaming machines for playing games of chance include various hardware components. One hardware component often found in gaming machines is a motherboard, also referred to herein as a “board.”
FIG. 1 is a block diagram of a conventional gaming machine 100 including a motherboard 105. The motherboard 105 is generally considered the main circuit board of the gaming machine 100, as it includes processor and memory chips enabling game play, connectors for attaching additional boards, mass storage interfaces, serial and parallel ports, expansion slots, and various controllers to control peripheral devices such as a display, player input mechanism, and hard drive or other storage medium.
Motherboards are mass-produced. These mass-produced boards, referred to herein as “off-the-shelf” motherboards, are made by various motherboard manufacturers, and can be purchased from any of a number of suppliers. FIG. 2 is a block diagram of a conventional off-the-shelf motherboard 105 and some of its components. These components include a CPU 205, a memory device such as RAM 210, a chip set 215, and a main BIOS chip 220. The use of off-the-shelf motherboards in gaming machines is desirable because the cost of new boards is reduced, as is the time required to change boards in a gaming machine. One of the reasons the cost is reduced is because a manufacturing assembly line does not need to match specific motherboards with specific BIOS chips or specific firmware releases.
FIG. 3 is a block diagram of a conventional BIOS 300, which can be provided as main BIOS 220 of motherboard 105. The BIOS, or “basic input-output system,” is essentially the built-in functionality on the motherboard that determines certain operations of the gaming machine without accessing programs from a storage medium such as a hard disk. For example, the BIOS can contain functions controlling boot-up operations, and controlling various peripheral devices coupled to the motherboard over a bus or other communications interface. The BIOS is often situated in a ROM chip mounted on the motherboard to ensure that the BIOS will generally be available and not be damaged by disk failures.
As mentioned above, one of the primary functions of the BIOS is to enable the gaming machine to be booted upon power-on or reset. In one implementation, the BIOS can be copied from ROM to RAM each time the game is booted. In another implementation, the gaming machine has a flash BIOS, i.e., the BIOS is programmed onto a flash memory chip mounted to the motherboard.
In FIG. 3, the BIOS 300 generally contains three functions, represented as modules in FIG. 3. These modules include “INIT” 305, “Video” 310, and “EXT” 315. The modules 305-315 in BIOS 300 implement boot-up functions when the gaming machine 100 is powered on or reset. The INIT module 305 brings the RAM 210 online, as well as the chip set 215, as shown in FIG. 2. In addition, the INIT module 305 enables access of a bus 230 on the motherboard, as shown in FIG. 2, such as a PCI bus. The video module 310 scans for signatures, and the EXT module 315 implements an extension stage of the boot up functionality. For example, as shown in FIG. 3, the EXT 315 module scans designated memory addresses C000:0 through E000:0 in order to call and test various devices on the motherboard 105 or coupled to the motherboard 105, such as RAM 210. Often, for example, the first card tested during the extension stage is a video card controlling the output of graphical information on a display of the gaming machine, assigned to memory address C000:0. Additional memory addresses scanned during the extension stage provide other functions, such as entering the BIOS set-up stage.
In gaming machines, there is a need to verify that the game data and other contents of a storage medium such as a hard drive or CD is authenticated. The motherboard of the gaming machine is often customized to achieve the desired authentication. The customized motherboard is referred to herein as a “custom motherboard.” In FIG. 2, one customization involves customizing the main BIOS chip 220, referred to herein as a “custom main BIOS,” to perform the desired authentication. Another common motherboard customization includes mounting a second BIOS chip 225, as shown in FIG. 2, to the board. The second BIOS chip 225 is itself customized to perform part or all of the desired authentication on that gaming machine. Accordingly, the second BIOS chip 225 is referred to herein as a “custom second BIOS.” The custom second BIOS alone or in combination with the custom main BIOS perform authentication of software and data, such as audio, video and other media files, received on the gaming machine.
Periodically, advances in motherboard hardware and related software lead to a desire to replace an existing motherboard in the gaming machine with a new motherboard. When the existing motherboard is removed from the gaming machine for replacement, of course all of the components mounted on the existing motherboard are removed with it. The removed components include both the custom main BIOS and any custom second BIOS. The new motherboard has a new main BIOS which needs to be customized in a specific manner to the new motherboard (i.e., often different from the custom main BIOS of the existing board). The new motherboard would also require the engineering and mounting of a new custom second BIOS on the board.
To save cost and time, what is needed is the ability to preserve the authentication processes when swapping motherboards in a gaming machine, for instance, without having to customize the main BIOS or build and mount a custom second BIOS to the new board. In other words, the authentication processes should be enabled regardless of the particular off-the-shelf motherboard inserted in the gaming machine.